KR100896110B1 - Propylene polymer with high crystallinity - Google Patents

Abstract

The present invention relates to a composition suitable for the manufacture of films having very useful stiffness-processability-balance comprising up to 1.6% by weight of decalin soluble material and high crystalline propylene polymers having a polymolecular index (PI) of at least 5.0.

Stiffness, processability, balance, propylene polymer, crystalline

Description

Propylene polymer with high crystallinity

FIELD OF THE INVENTION The present invention relates to high crystalline propylene polymers suitable for films, methods for their preparation and their use.

The stiffness-processability-balance of the propylene polymer depends on the end use for which it is used. In applications such as biaxially stretched films where good stretchability is required, it is difficult to obtain a propylene polymer that combines high rigidity and good processability. Highly crystalline propylene polymers made using the latest high-yield fourth and fifth generations of Ziegler-Natta catalysts provide high rigidity, but their processability is typically difficult to solve: Highly crystalline propylene has a low elasticity compared to similar polymers made using, for example, what is known as the second generation of Ziegler-Natta catalysts with low catalytic activity. In order to improve the processability of high crystalline propylene polymers made with high-yield Ziegler-Natta catalysts, for example, a small amount of comonomer is introduced into the polymer (see eg EP339,804 to Exxon). It became. The addition of comonomers results in low isotacticity of such polypropylenes, thus resulting in low melting temperatures which improve processability for biaxially stretched polypropylene film applications. However, these improved processing properties result in reduced stiffness of the film.

In addition, low melt flow rates (MFR) and wide molecular weight distributions (MWD) are known to contribute to good processability. However, the stiffness-processability-balance remains a challenge. This is because the second generation catalysts are still conveniently used to produce viable polymers for the film application, although they are less beneficial due to their low activity and typical requirements of additional process steps such as washing polymerized polymer products. It can be seen from the facts. Thus, the production range for propylene polymers having the above rigid-processability-balance is limited.

International Patent WO2004 / 013193 discloses at least 97% isotactic pentad (mmmm), M _w / M _n equal to or greater than 6 A polypropylene having a ratio and an M _z / M _w ratio equal to or greater than 5.5 is disclosed. However, no rigid-processability-balance of propylene polymers is mentioned. In addition, no mention of isotacticity distribution and isotactic sequence length for polymers was found.

Thus, further development of new propylene polymers characterized by good stiffness-processability-balance to suit particular end applications such as specially biaxially oriented films used in packaged articles, or articles for electrical applications such as capacitor films. This is constantly being demanded.

It is therefore an object of the present invention to expand the product range of polypropylene materials which are therefore required for end use. More specifically, the object of the present invention is for film application applications, including the use for application to propylene polymers having very advantageous rigid-processability-balance, in particular biaxially stretched polypropylene films.

Surprisingly, it has been found that the above-mentioned objects can be obtained by propylene polymers having high crystallinity and broad molecular weight distribution.

An indicator for the crystallinity of a polymer is the amount of its decaline and / or xylene soluble material fraction. The decalin and / or xylene solubles fraction contains a polymer chain with low molecular weight and low stereo regularity. Therefore, since the propylene polymer of the present invention is highly crystalline, the amount of decalin polymer and / or xylene soluble substance fraction should be low.

On the other hand, the propylene polymer of the present invention also has a wide molecular weight distribution (MWD), in which the wide MWD increases the processability of the polymer and further tailors the mechanical and / or processing properties of the polymer as required for the end use purpose. This is because it provides a viable means. The molecular weight distribution (MWD) can be determined by SEC (also known as GPC), expressed herein as M _w / M _n , or by Polydispersity Index (PI) -Measurement or Shear Thinning Index ( Can be measured by rheological measurements such as SHI) -measurement. All such measurements are known and further defined in the "Definitions and Determination Methods" below.

The polymers of the present invention are propylene polymers having up to 1.6% by weight of decalin soluble material, preferably up to 1.3% by weight. Furthermore, the propylene polymers of the invention have a polydispersity index (PI) of at least 5.0, generally at least 5.5, preferably at least 6.

Thus, for the reasons given above, the present invention relates to a highly crystalline propylene polymer having up to 1.6% by weight, preferably up to 1.3% by weight, of decalin soluble material. Furthermore, the propylene polymers of the invention have a polydispersity index (PI) of at least 5.0, generally at least 5.5, preferably at least 6. Combinations of the above provide a very workable stiffness-processability-balance.

In one preferred embodiment, the decalin soluble material is 1.0 wt% or less, more preferably 0.8 wt% or less.

Furthermore, the propylene polymer preferably has up to 2% by weight, preferably up to 1.5% by weight of xylene soluble material. In another embodiment, the XS of the propylene polymer is as low as 1.4 wt% or less, more preferably no greater than 1.3 wt%, or even no greater than 1 wt%.

In the present invention, it is important that the propylene polymer has high crystallinity. In order to obtain high crystallinity, the propylene polymer must have high isotacticity. Therefore, it is preferred that the propylene polymer appears to have an isotactic degree of at least 97% mmmm pentad, more preferably at least 97.5%, which are measured by the method of ¹³ C-NMR.

Furthermore, the propylene polymers generally have an isotactic sequence length of at least 150, preferably at least 200, more preferably at least 300, and are defined as ¹³ C as defined under "Definitions and Determination methods" defined below. Measured as meso run length values by the method of -NMR Depending on the end-use, in some embodiments of the present invention even a sequence length of 400 or more is also useful and can thus be included in the present invention. The longer this becomes, the higher the crystallinity of the material is.

Typically higher isotacticity requires narrower process range and higher stretch. The fact that the propylene polymer of the present invention additionally has a wide molecular weight distribution (MWD) is a benefit to the improved processability and stretchability of the propylene polymer.

Another indicator of a broad molecular weight distribution is the ratio of M _w / M _n measured in SEC, which is equivalent to the polymolecular index (PI). Therefore, the ratio of M _w / M _n is 5 or more, preferably 5.5 or more, and more preferably 6 or more. On the other hand, the upper limit of the M _w / M _n ratio is 20 or less, preferably 10 or less, more preferably 9 or less, and even more preferably 8.5 or less.

Furthermore, the molecular weight of a polymer can be further expressed by its melt flow rate (MFR) method. An increase in molecular weight means a decrease in MFR-value. Melt flow rate (MFR ₂ ) is preferably measured as described under “Definition and Measurement Methods” below.

MFR ₂ is preferably 2 to 6 g / 10 min, preferably 2 to 5 g / 10 min.

Furthermore, as mentioned above, the Shear Thinning Index (SHI) is a very delicate indicator of MWD. The higher the SHI value, the wider the MWD. Therefore, the propylene polymer of the present invention preferably has a SHI (0/50) of 12 or more, preferably 14 or more, more preferably 16 or more. Usually SHI (0/50) may vary from 15 to 22, preferably from 16 to 20. In another aspect, 16 to 18 SHIs (0/50) are feasible.

Advantageously, propylene polymers generally have significantly higher melting temperatures. Therefore, 162 degreeC or more is preferable, and, as for melting temperature, 163 degreeC or more is more preferable.

It is also preferred that the propylene polymer has at least 50% crystallinity as measured by DCS. Furthermore, the crystallization temperature (T _cr ) is preferably 110 ° C. or higher, more preferably 113 ° C. or higher, for example, between 110 ° C. and 122 ° C., such as from 115 ° C. to 120 ° C. without the addition of a nucleating agent. Between. The crystallization of the propylene polymer and thus the crystallization temperature (T _cr ) can be further increased by methods known in the art, for example by the addition of nucleating agents during or after the polymerisation of the polymer. In one embodiment, the propylene polymer is prepared in the presence of a nucleating agent such that the composition has a crystallization temperature (T _cr ) of 118 ° C. or higher.

According to a preferred embodiment, the propylene polymer has the same distribution of the isotactic sequence in the long isotactic sequence and the polymer chain, where the combination further contributes to both high crystallinity and good processability.

The determination of the isotactic sequence length distribution is performed by a temperature raising elution fraction (TREF) technique (described in detail in the Examples section below) that fractionates propylene polymers according to differences in solubility. It has been clearly demonstrated in the propylene polymer that the TREF technique fractionates the propylene polymer according to the longest crystalline sequence in the chain, which increases almost linearly at the elution temperature. Here, the higher the maximum temperature T _p , the higher the mass mean temperature T _w of the TREF curve, and the longer the isotactic sequence.

Therefore, the highly crystalline propylene polymer preferably has the following characteristics:

a) T _p at least 122.5 ° C., more preferably at least 123 ° C .; And

b) T _w at least 118 ° C., more preferably at least 119 ° C.,

Here, T _p and T _w are calculated from the temperature rising elution fraction (TREF) function of the propylene polymer in the range of 80 to 140 ° C.,

Where T _p is the maximum temperature of the TREP function,

T _w is the mass mean temperature of the TREP function defined by

T _i is the temperature at which the eluent concentration C _i was measured and C _i is the concentration of the eluate at the temperature T _i .

TREF measurements can be performed as described generally in the "Definition and Measurement Methods" below, using a TREF instrument incorporating software for the above and the following calculations.

It is particularly preferable that the propylene polymer according to the invention has a sigma value of 10 ° C. or less, where sigma is defined as follows.

Here, each variable of this equation is obtained from the TREF-function defined above. The sigma values represent useful isotactic sequence distributions of the present invention.

Furthermore, the propylene polymer preferably has a T _p / R ratio of at least 75 ° C, preferably at least 80 ° C, more preferably at least 85 ° C. In another aspect of the invention, the propylene polymer T _p / R ratio can be up to 90 ° C. or higher, depending on the end use. T _p / R is obtained from the TREF-function defined above, where R is defined as follows:

In this case, T _n is the number average temperature of the TREF function defined by the following equation.

The T _p / R ratio is an indicator for uniform isotactic sequence distribution as well as long isotactic sequence lengths. T _p / R increases with increasing isotactic sequence length and decreasing isotactic sequence length distribution. Therefore, the T _p / R ratio is another indicator for balanced stiffness-processability because the long isotactic sequence length contributes to the crystallization of the propylene polymer and the uniform sequence distribution improves the processability.

Another indicator of long isotactic sequence length and uniform sequence distribution is the SDBI value defined by the solubility distribution index of the following equation.

Low values of SDBI also indicate narrow TREF curve peaks and even isotactic sequence length distributions. Therefore, it is preferable that SDBI is 24 degrees C or less.

Furthermore, it is advantageous that the amount of catalyst residues in the polymer is small. Therefore, the propylene polymer preferably has an Al-content of 50 ppm or less, more preferably 48 ppm or less. Preferably, the Al-content, i.e., reactor powder obtained directly from the propylene polymer after the polymerisation step, without any post-reactor treatments such as washing steps to remove or reduce the aluminum in the propylene polymer. It is preferable that the Al-content of the powder) is small. Reactor powder is also called propylene polymer made into the reactor. Depending on the end use it is possible, if necessary, to further wash the product produced in the reactor to reduce any additional unwanted residues contained therein.

The present invention includes both homopolymers of propylene and copolymers of propylene and one or more alpha-olefins comprising ethylene, preferably random copolymers, but homopolymers are preferred. In the case of random copolymers, it is preferred that only a small amount of comonomers be bonded to the propylene chain, preferably not more than 0.2% by weight, more preferably not more than 0.1% by weight, even more preferably not more than 0.05% by weight. Even more preferably 0.005% by weight or less, with other alpha-olefins more preferred than propylene in the polymer. The comonomer is preferably at least ethylene.

According to a preferred embodiment the propylene polymer has a wide MWD and comprises at least two propylene polymer components having different weight average molecular weights (M _w ) and different melt flow rate ratios (MFR). Low molecular weight (LMW) components have a higher MFR than high molecular weight (HMW) components. MFR ₂ of LMW Components And MFR ₂ of HMW components The ratio between them is generally 30 or more, preferably 40 or more, more preferably 50 or more. The upper limit of the ratio (MFR _{2 of} LMW): (MFR _{2 of} HMW) is up to 400, preferably up to 200.

Preferably, the propylene polymer is of bimodal type with LMW-component and HMW-component. The amount of LMW-component is generally 30 to 70% by weight, preferably 40 to 60% by weight of the total amount of propylene polymer. On the other hand, the amount of HMW-component is generally 30 to 70% by weight, preferably 40 to 60% by weight of the total amount of propylene polymer. Preferably both components are homopolymers as defined above. It provides a very advantageous MWD for the final propylene polymer with respect to molecular weight distribution, multimodality type, preferably bimodality type.

According to a preferred embodiment, the propylene polymer of the present invention is a reactor-produced propylene polymer and has at least T _p and T _w values as defined in the claims below. More preferably, one or more of the following properties of the reactor-produced propylene polymer are as described above or in the claims: T _p / R, σ, SDBI, MWD, XS, PI, decalin soluble material, isotactic At least one of isotacticity index, isotactic sequence length and MWD, preferably XS, PI or decalin soluble material.

Reactor-produced propylene polymer means here a reaction product as obtained by the polymerization process, ie reactor-produced propylene polymer means 1) Al or other residues resulting from the catalyst, or 2) XS Or a fraction of the soluble polymer determined from the decane soluble material (e.g. for an increase in isotacticity), or no washing or processing steps for the reduction or removal of both 1) and 2). Of course, if desired, the reactor-produced propylene polymer of this embodiment is then subjected to subsequent treatment steps, eg washing steps, and further tailoring, for example of the Al residues and / or soluble polymer fractions of the product. It can be treated by known methods for further reduction.

More preferably, the propylene polymers of the present invention are obtained from Ziegler-Natta catalysts, and more preferably may be obtained by high purity fourth or fifth generation Ziegler-Natta catalysts.

The present invention also provides a process for producing a propylene polymer, wherein the propylene monomer and optionally one or more comonomers are polymerized together in the presence of a polymerization catalyst. If the propylene polymer consists of only one component, the process is a single-stage process.

In principle, any polymerization method can be used to prepare the propylene polymer, including solution, slurry and bulk or gas phase polymerizations. Bulk in the present invention means polymerisation in the reaction liquid containing at least 60% by weight monomer.

The present invention further provides a process for producing propylene polymers comprising two or more different propylene polymer components having different molecular weights as defined above, wherein each polymer component is one in the presence of a polymerization catalyst. Or by polymerization of propylene monomers, optionally with one or more comonomers, in a multistage polymerization process using more than one polymerization reactor. Each step can be performed in parallel or in succession using similar or different polymerization methods. In the case of successive steps, the polymer constituents may be prepared by any order in which each step is carried out except for the first step in the presence of the formed polymer constituents, preferably the catalyst is used in the running step.

Although the preferred method for producing multimodal polypropylene is a multi-step process in which each or part of the components is mixed in situ during its polymerization process, the present invention also provides for two or more separately prepared processes. Propylene polymer constituents include mechanical mixing, which is mechanically mixed by methods known in the art.

Preferably, one of the propylene polymer constituents is prepared in a slurry process and the other polymer constituent is preferably prepared by gas phase polymerisation in a gas phase reactor so that the propylene polymer is at least bimodal with respect to MWD, preferably LMW-component and HMW-component as defined above are included.

In a preferred embodiment of the invention there is also provided a process for the preparation of the propylene polymer of the invention comprising at least one propylene homo or copolymer component and optionally added propylene homo or copolymer component, wherein the process is It includes the following steps:

a) in a slurry reactor, such as a loop reactor, with the propylene monomer and optionally further one or more copolymers to polymerize to prepare the primary propylene polymer under the polymerization catalyst, optionally the reaction product of step a) Moving to the next gas phase reactor, and

b) obtaining the final propylene polymer by polymerizing together the propylene monomer and optionally one or more comonomers in the gas phase reactor to produce a secondary propylene polymer in the presence of the reaction product of step a).

The propylene polymer obtained from this embodiment is one preferred example of a reactor-produced propylene polymer.

In the case of bimodal propylene polymers or more as defined above, the HMW-component is preferably prepared in step (a) and the LMW-component is then present in the presence of the reaction product of step (a) obtained from the primary reactor. Prepared in step (b).

The process comprising more than steps (a) and (b) is very useful, which is very preferably high crystalline propylene for obtaining wide MWD, and also selective stereochemistry (preferably up to the distribution and length of the isotactic sequence). This is because it serves as a viable means for producing a propylene polymer having a polymer, preferably a reactor-produced multimodal, more preferably a bimodal. In addition, the process has enabled the use of fourth or fifth generation Ziegler-Natta catalysts to produce the propylene polymers of the present invention in state-of-the-art, significantly higher yields. According to the invention there is further provided a propylene polymer obtainable by any of the above described processes, preferably by the above process comprising at least steps (a) and (b).

This preferred multi-step process is specifically carried out by a loop-gas phase process (such as Borélias A / S of Denmark known as Borstar ^® Technology) as described in EP 887,379 and WO 92/12182, respectively. Developed). The documents are incorporated herein by reference.

In a preferred embodiment the propylene polymer is a homopolymer polymer, preferably at least a bimodal propylene homopolymer, and can be obtained by any of the processes described above or according to the claims.

In the case of random copolymers, comonomers can be introduced in any of steps (a) and / or (b) in the above preferred multi-step process.

The properties of the polymer composition are controllable and controllable in the process conditions of known methods and include, for example, one or more of the following process parameters: temperature, hydrogen supply, comonomer feed, catalyst, external donor Type and amount (if used), the split between two or more components of the multimodal polymer, for example between the components obtained from steps (a) and (b).

Preferably, the embodiment comprises process steps (a) and (b), wherein the polymerisation conditions for the one stage slurry reactor are as follows:

The temperature is in the range of at least 80 ° C., preferably at least 85 ° C .;

The pressure is in the range of 20 to 80 bar, preferably 30 to 60 bar; Hydrogen is added to control the molar mass in a manner known in the art,

The reaction mixture in the slurry (bulk) reactor is transferred to the next gas phase reactor, ie step b), wherein the polymerization conditions are preferably as follows:

The temperature is in the range of at least 85 ° C., preferably at least 90 ° C .;

The pressure is in the range of 5 to 50 bar, preferably 15 to 20 bar, most preferably 50 to 35 bar;

Hydrogen may be added to control the molar mass known in the art.

Particularly preferably, the temperatures of the polymerisation steps (a) and (b) are at least 80 ° C. and the temperature in each step is the same or alternatively the temperature in the gas phase step (b) is higher than the slurry reactor step (a). .

The propylene polymer obtained can be further worked up, for example the propylene polymer is pelletized by using an extruder as is known in the art. Furthermore, it will be apparent to those skilled in the art that conventional additives may be used.

In principle, the compositions of the present invention may be used with any polymerisation catalyst, such as a Ziegler-Natta type catalyst, a single site catalyst comprising metallocene and non-metallocenes. Can also be prepared. The catalyst may be based on one or more transition metal catalysts, or late transition metal catalysts, or any combination thereof. The efficacy of this type of catalyst is apparent in the art.

Preferred catalysts are Ziegler-Natta catalysts, specifically the fourth and fifth generation types of high-yield Ziegler-Natta catalysts, which are catalyst components, co-catalyst components and one or more electron donors (internal And / or an external electron donor, preferably at least an external donor). Preferably, the catalyst component is a Ti-Mg based catalyst component and the cocatalyst generally is an Al-alkyl based compound. Examples of suitable catalyst references are described in US Pat. No. 5,234,879, WO 92/19653, WO 92/19658, and WO 99/33843.

Preferred outer donors are known silane-based donors, preferably dicyclopentyl dimethoxy silane or cyclohexyl methyl dimethoxy silane.

Nucleating agents can also be added to the propylene polymer as mentioned above. It is preferably added during the polymerisation process of the propylene polymer. One method of adding a nucleating agent is to use a modified catalyst system comprising a nucleating agent known in the art and is described, for example, in WO 99/24478 and WO 99/24479.

Propylene polymers have excellent stretch properties as demonstrated in Tables 1-3 of the Examples section below and FIGS. 1-3.

Thus, the propylene polymers of the present invention can be used for a variety of end uses. The rigid-processability balance of polymer production is well suited for a variety of film applications, especially biaxially oriented film applications.

Compared to film applications where the comonomer is bonded to the propylene polymer for improved processability, the propylene polymer of the present invention has a very long isotactic sequence length as well as a very uniform isotactic sequence distribution, which results in the features defined above. Also have.

Furthermore, propylene polymer compositions also have good barrier properties useful for, for example, packaging materials.

The propylene polymers are well suited for the desired end use, such as for application to capacitor films. High purity levels are also required in capacitor film applications and, depending on the requirements, the propylene polymers of the present invention may be subjected to additional washing steps if desired to further reduce the amount of catalyst residues, such as Al residues.

The invention also encompasses films, in particular biaxially oriented films, comprising the propylene polymer of the invention as defined above. The film may be a single layer film comprising, or preferably consisting of, propylene polymers. Alternatively, the film may be a multilayer film comprising propylene polymer in one or more layers of the film. The propylene homopolymer in the multilayer film preferably forms a substrate (or support) layer.

The film can be made according to or similar to methods known in the art.

The propylene polymers of the present invention may also be further mechanically blended into other polymer components depending on, for example, the end use. Such mixing is also included in the present invention.

Definitions and Determination methods

Terms and measurement methods for measured properties used for the definition of the invention generally apply to the above detailed description and the examples and the following claims, if not otherwise mentioned:

TREF analysis: Temperature rising elution fraction (TREF) analysis is known.

Instrument: CRYSTAF-TREF 200 instrument with software for calculating parameters and expressions (Manufacturer: Polymer CHAR, Spain)

Solvent: 1,2,4-trichlorobenzene stabilized with 300 ppm BHT; (TCB)

Concentration: 80 mg in 20 ml TCB

Measuring condition: crystallization rate: 0.5 ℃ / min (between 95 ° -40 °),

Elution rate: 1.00 ° C./min (between 40 ° -140 °) and pump flow rate: 0.5 mL / min.

The parameters and equations used to describe the high isotacticity level and uniform isotacticity distribution (= isotactic sequence distribution) are calculated from the TREF curves formed as follows: Statistical parameters are calculated from the following equations and the software of the TREF instrument: Is calculated using:

Tp = maximum temperature

Tw = weight average temperature

Tn = number average temperature

It is typically understood that other measurement methods can be used to obtain results corresponding to the above measurement methods (within the limits of measurement accuracy demonstrated by the skilled person).

Melting temperature T _m , crystallization temperature T _cr , and crystallinity: measured by Mettler TA820 differential scanning calorimetry; (DSC) on a sample of 3 ± 0.5 mg. Both crystallization and melting curves were obtained during 10 ° C./min cooling and heating scan between 30 ° C. and 225 ° C. Melting and crystallization temperatures were obtained as peaks of endotherms and exotherms. The degree of crystallinity was calculated by comparing the heat of fusion of the fully crystalline polypropylene, ie 209 J / g.

NMR: C ¹³ NMR spectra of polypropylene were obtained from samples dissolved in 1,2,4-trichlorobenzene / benzene-d6 (1,2,4-trichlorobenzene / benzene-d6) (90/10 w / w). Recorded on Bruker 400MHz spectrometer at 130 ° C.

The assignment for the pentad analysis was performed according to the method described in the paper: T. Hayashi, Y. Inoue, R. Chujo, and T. Asakura, Polymer 29 138-43 (1988) and Chujo R, et al, Polymer 35 339 (1994) .

Isotactic sequence length is expressed as meso run lengths measured from mmmm and mmmr pentad

SEC: the weight average molecular weight (M _w ) and the number average molecular weight (M _n ) and as an example the molecular weight distribution (MWD, M _w / M _n ) of the polymer are operated at 135 ° C. and two mixed beds and It was measured on a Millipore Waters ALC / GPC equipped with one 10 ⁷ mm TSK-Gel column (TOSOHAAS 16S) and other refractometer equipment. Solvent 1,2,4-trichlorobenzene was provided at a flow rate of 1 ml / min. The column was calibrated with narrow molecular weight distribution polystyrene standards and narrow wide polypropylene.

Multimodality, including bimodality for molecular weight distribution (MWD), means that the polymer comprises two or more polymer components with different MFR's (and as an example M _w 's). Preferably the polymer component of the multimodal polymer is prepared in each of two or more separate reactors, so that the product produced from each reactor has said other MFR's and M _w 's.

MFR ₂ : measured according to ISO 1133 (230 ° C, 2.16 kg load). For example, preferably the LMW and HMW components of the propylene polymer as defined above are different MFR _{2 because the} LMW component has a higher MFR than the HMW component. Has a value.

Weight-% is reduced to w% or wt-%.

Xylene soluble material (XS, wt%): Analysis according to the known method: 2.0 g of the polymer is dissolved with stirring in 250 ml p-xylene at 135 ° C. After 30 ± 2 minutes, the solution is cooled at room temperature for 15 minutes and then precipitated at 25 ± 0.5 ° C. for 30 minutes. The solution is filtered and concentrated in a nitrogen stream and the residue is dried under vacuum at 90 ° C. until constant mass is reached.

XS% = (100 xm ₁ xv ₀ ) / (m ₀ xv ₁ ),

Where m ₀ = initial polymer amount (g)

m ₁ = mass of residue (g)

v ₀ = initial volume in ml

V ₁ = sample volume analyzed (ml)

Decalin solubles: 2 g polymer samples are dissolved in 100 ml decalin (decahydronaphthalene) with heating at 160 ° C. and stirring for 1 hour. The solution is cooled for 1 hour at room temperature and then at 25 ° C. for 1 hour. The precipitated insoluble portion is filtered and vacuum dried at 140 ° C. The total solids content of the filtrate is measured for the solution fraction. It is calculated as decalin soluble substance = [(grams of residue) / (grams of sample)] x 100%.

Flexibility: Samples of about 85 mm x 85 mm were biaxially rolled from cast-film (film with a thickness of 1 mm) to experimental film stretcher KARO IV (Bruckner Maschinenbau Gmbh, siegsdorf, Germany) Cut with credit Drawing is carried out at temperatures in the range of 160-165 ° C.

Rheology: Dynamic rheological measurements are carried out with rheology RDA-II QC using samples compression-molded using 25 mm-diameter plates and geometric plates under nitrogen atmosphere at 200 ° C. Oscillatory shear experiments are conducted within a linear viscoelastic range of strain at a frequency of 0.01 to 500 rad / s (ISO6721-1).

The values of storage modulus (G '), loss modulus (G' '), complex modulus (G *), and complex viscosity (η *) are functions of frequency Obtained as (ω).

Zero shear viscosity (η ₀ ) is the reciprocal of the compound viscosity, calculated using a defined compound flow rate. Its real and imaginary parts are defined as follows.

f '(ω) = η' (ω) / [η '(ω) ² + η''(ω) ² ] and

f '' (ω) = η '' (ω) / [η '(ω) ² + η''(ω) ² ];

At this time,

η '= G' '/ ω and η' '= G' / ω

f '(ω) = G''(ω) * ω / [G' (ω) ² + G '' (ω) ² ]

f '' (ω) = G '(ω) * ω / [G' (ω) ² + G '' (ω) ² ].

The polydispercity index, PI, is calculated by the intersection of G '(ω) and G' '(ω).

There is a linear correlation between f 'and f''with a zero ordinate of 1 / η ₀ (Heino et al ¹ ).

For polypropylene this is valid at low frequencies and five first points (5 points / decade) are used to calculate η ₀ .

The elasticity index G 'and the shear thinning index SHI are correlated with the MWD and independent of the MW, and are calculated according to Heino ^{1 ), 2)} (below).

SHI is calculated by dividing the zero shear viscosity by the composite viscosity value and is obtained from an accurate and consistent shear stress value, G *. In short, SHI (0/50) is the ratio between the zero dedicated viscosity and the viscosity at a shear stress of 50000 Pa.

1) Rheological chracterization of polyethylene fractions. Heino, EL; Lethtinen, A; Tanner, J .; Seppala, J. Neste Oy, Porvoo, Finland. Theor. Appl. Rheol., Proc. Int. Congr. Rheol., 11 ^th (1992), 1 360-362

2) The influence of molecular structure on some rheological properties of polyethylene. Heino, Eeva-Leena. Borealis Polymers Oy, Porvoo, Finland. Annual Transactions of the Nordic Rheology Society, 1995

-The term "random copolymer" is distributed in the present invention by the comonomer of said copolymer optionally, ie, by statistically inserting the comonomer unit into the copolymer chain.

The comonomer content (% by weight) can be measured by known methods based on Fourier Transform Infrared Spectrometer (FTIR) measurements, corrected by C ¹³ -NMR.

State-of-the-art, high-yield fourth or fifth Ziegler-Natta (ZN) catalysts represent an additional generation of ZN catalysts developed after the second generation ZN catalysts, whose catalytic activity is 2 as known in the art. It is significantly higher than the activity of the first generation ZN catalyst.

Al content is measured by ICP spectrometer (inductive pair plasma emission). The instrument for Al-content measurement is the ICP Optima 2000 DV, PSN 620785 (manufactured PerkinElmer instrument, Belgium), with the instrument's software. The polymer sample is first ashed as in known methods and then dissolved in a suitable acidic solvent. Dilution of the standard solution for the calibration curve is dissolved in the same solvent as the sample and the sample concentration is chosen to be within the standard calibration curve (ppm: means 1/1000000 by mass).

The invention is illustrated by the following examples.

Raw materials may be commercially available unless otherwise described, or may be prepared according to the known methods described in the text or in a similar manner.

Examples 1 and 2

Polymerization

The catalyst used for the polymerization was known and was a stereospecific transesterified MgCl ₂ -supported Ziegler-Natta catalyst prepared according to US Pat. No. 5,234,879, which has the latest high-yield, ie high activity. The catalyst was contacted with triethylaluminum, such as a promoter and external donor, and then prepolymerized in a known manner in the presence of propylene and promoter in a separate prepolymerisation step. In both Examples 1 and 2 the Al / Ti ratio was 200 mol / mol and the Al / donor ratio was 5 mol / mol.

Polymerization was carried out in a multistage process on a pilot scale including a continuous loop reactor and a fluidized bed gas phase reactor. Propylene and hydrogen were fed together with the activated catalyst to a loop reactor operating like a bulk reactor at the conditions given in Table 1 (step (a), defined above, preparation of the primary propylene polymer component). The polymer slurry stream is then fed from the loop reactor to the gas phase reactor and further propylene and hydrogen are added to the gas phase reactor (step (b) as defined above, to obtain the propylene polymer of the present invention; (a) Of the second propylene component in the presence of the reaction product). Polymerization conditions in the gas phase are also described in Table 1. Table 1 also describes the polymer properties of the loop, gas phase and final product.

The polymers of Comparative Examples 1 and 2 were of commercially available grades, both of which were made using known second generation Ziegler-Natta catalysts. The properties of these comparative materials are shown in Table 2 and the figures.

Table 1

Example 1 Example 2 Catalyst type Donor type Dicyclopentyl dimethoxy silane Dicyclopentyl dimethoxy silane Al / Ti ratio (mol / mol) 200 200 Al / donor ratio (mol / mol) 5,0 5,0 Loop Temperature (℃) 85 85 Split% 55 58 MFR ₂ (g / 10min) 0,6 0,5 XS (%) 1,7 2,0 GPR Temperature (℃) 85 85 Split% 45 42 Calculated MFR ₂ (g / 10min) 55 100 Final propylene polymer MFR ₂ (g / 10min) 3,6 3,4 XS (%) 1,3 1,2 ETA0, zero viscosity (pas) 10826 13802 SHI (0/50) 17,8 20,0 PI 6,1 6,0 Tm (℃) 163.5 166,4 Crystallization (cryst) (%) 52.7 54,4 T _cr (℃) 118,4 123,9 Moisture barrier Permeability g / m2 / 24h 4,2 4,3

TABLE 2

unit Example 1 Comparative Example 1 Comparative Example 2 MFR g / 10min 3,6 3,1 3,4 AL ppm 47,0 2 9,5 TI ppm <1,0 One 0,9 mmmm pentad % 97,65 94.25 91.84 Method length 574 90.0 70 Decal Soluble Substances weight% 0,7 1,6 3,4 XS % 1,3 1,2 3,2 ETA 0 Pa * s 10826 11103 10766 SHI (0/50) none 17,8 12,8 12,9 PI 1 / Pa 6,1 5,32 5,2 M _w mol / g 430000 439000 440000 M _n mol / g 54000 64600 62000 MWD 8 6,8 * 7,1 T _m ℃ 163,5 163,1 159,3 Crystallinity % 52,7 52,9 48 T _cr ℃ 118,4 114,7 112 Moisture barrier Permeability g / m2 / 24h 4,2 4,3 6,6

As can be seen from Table 2, the propylene polymer of the present invention has an improved isotactic sequence length (meso run length) over the prior art.

TABLE 3

Example 1 Comparative Example 1 Comparative Example 2 Elution temperature, ℃ Cumulative fraction,% 98 % 3,0 4,4 7,4 110 % 7,7 12,0 17,4 120 % 29,5 43,5 62,0 122 % 42,2 70,6 88,9 125 % 85,2 99,3 99,6 T _p ℃ 123,8 122,4 120,8 T _w ℃ 119,93 117,35 114,86 r 1,013 1,017 1,028 R 1,319 1,665 2,848 σ ℃ 9,72 10,73 13,32 SDBI ℃ 23,84 24,62 27,93 T _p / R ℃ 93,85 73,53 42,41

Propylene polymer compositions suitable for the manufacture of the films of the present invention include bicrystalline stretching by having a highly useful stiffness-processability-balance that includes highly crystalline propylene polymers having a decalin soluble material of less than 1.6% by weight and a monomolecular index (PI) of 5.0 or greater. Since the film can be suitably used for various end purposes, it is a very useful invention for various industries.

Claims (27)

Up to 1.3% by weight of decarin soluble material; And Up to 2% by weight of xylene soluble material; Made up of The polydispersity index (PI) measured from G '(ω) and G "(ω) measured according to ISO 6721-1 is at least 5.0, A high crystalline propylene polymer, characterized in that the isotactic sequence length measured by meso run length value by the method of ¹³ C-NMR is 150 or more. The high crystalline propylene polymer of claim 1, wherein the propylene polymer has a chain isotacticity index (mmmm pentad) of at least 97% as measured by ¹³ C-NMR. The high crystalline propylene polymer of claim 1, wherein the propylene polymer is measured by Size Exclusion Chromatography (SEC) and has a M _w / M _n of 5 or more. The high crystalline propylene polymer of claim 1, wherein the propylene polymer is measured according to ISO 1133 (230 ° C., 2.16 kg load) and has an MFR ₂ of 2 to 6 g / 10 min. The high crystalline propylene polymer according to claim 1, wherein the propylene polymer is measured by a differential scanning calorimetry (DSC) method and has a melting temperature (T _m ) of 162 ° C. or higher. The propylene polymer of claim 1, wherein the propylene polymer is measured by a differential scanning calorimetry (DSC) method and has a crystallization temperature (T _cr ) of 113 ° C. or higher. The high crystalline propylene polymer of claim 1, wherein the propylene polymer is measured from a differential scanning calorimetry (DSC) method and has a crystallinity of 50% or more. The high crystalline propylene polymer according to claim 1, wherein the propylene polymer has an aluminum (Al) content of 50 ppm or less. The high crystalline propylene polymer of claim 1, wherein the propylene polymer is a homopolymer. The high crystalline propylene polymer of claim 1, wherein the propylene polymer is a multimodal polymer with respect to molecular weight distribution. The high crystalline propylene polymer of claim 1, wherein the propylene polymer is a multimodal polymer with respect to molecular weight distribution and comprises two propylene polymer components having different weight average molecular weights (M _w ). The low molecular weight (LMW) fraction of 30 to 70% by weight according to claim 1, wherein the propylene polymer is a multimodal polymer with respect to molecular weight distribution and comprises two propylene polymer components having different weight average molecular weights (M _w ). And a high molecular weight (HMW) fraction 70 to 30% by weight. The high crystalline propylene polymer of claim 1, wherein the propylene polymer is made of a reactor. Process for producing a high crystalline propylene polymer according to any one of claims 1 to 13, characterized in that the high crystalline propylene polymer is prepared in the presence of a catalyst in a multistage process comprising a slurry reactor and a gas phase reactor. The process of claim 14 comprising the following steps: a. Polymerizing propylene with the primary polymerisation product in a first reaction zone comprising a slurry reactor; b. Then transferring the primary polymerized product to a secondary reaction zone containing a gas phase reactor; And c. Continuously polymerizing propylene in the gas phase in the presence of said primary polymerisation product. The process of claim 14, wherein the temperature in the slurry reactor and the gas phase reactor is at least 80 ° C. 16. 15. The process of claim 14 wherein the temperature in the gas phase reactor is higher than in the slurry reactor. 15. The process of claim 14, wherein the high molecular weight (HMW) fraction is prepared in the first reaction zone and the low molecular weight (LMW) fraction is prepared in the secondary reaction zone. A film comprising the high crystalline propylene polymer according to claim 1. 20. The film of claim 19, wherein the film is biaxially stretched. delete delete delete delete delete delete delete

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